title: Warthin tumor. A new hypothesis concerning its development.
abstract: OBJECTIVE
  Warthin tumor is the second most common benign parenchymal salivary neoplasm. The purpose of this study was to evaluate the histopathologic features of Warthin tumor to determine whether a developmental pattern could be identified.
  
  
  METHODS
  Seventy-nine Warthin tumors in 63 patients (62 male and 1 female; average age, 58.62 years) were examined. All cases were histopathologically classified and morphometrically analyzed with an Optomax system to measure the proportions of lymphoid tissue and cystic cavities.
  
  
  RESULTS
  The predominantly epithelial type (21% of all cases) of Warthin tumor was associated with a mean patient age at diagnosis of 53 years, a mean evolution time of 2.8 months, an average size of 1 cm, and a mean lymphoid component of 10%. In the case of the classical type (61% of all cases), the mean patient age at diagnosis was 58 years, the mean evolution time 9 months, the average size 2.4 cm, and the mean lymphoid component 40%. For the predominantly lymphoid type (18% of all cases), these values were, respectively, 62 years, 11 months, 2.8 cm, and 74%. The mean size of the classical and lymphoid tumors (79% of the Warthin tumors) was significantly greater (p < 0.0001) than the mean size of the epithelial type (21% of the Warthin tumors). A positive correlation between tumor size and evolution time was found.
  
  
  CONCLUSIONS
  Our results suggest that the Warthin tumor initially develops as an adenomatous epithelial proliferation followed by lymphocytic infiltration.
authors.affiliation: Department of Stomatology, Hospital de Cruces, Vizcaya, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Aguirre
authors.forename: M A
authors.initials: MA
authors.lastname: Echebarría
authors.forename: R
authors.initials: R
authors.lastname: Martínez-Conde
authors.forename: C
authors.initials: C
authors.lastname: Rodriguez
authors.forename: J J
authors.initials: JJ
authors.lastname: Burgos
authors.forename: J M
authors.initials: JM
authors.lastname: Rivera
mesh_terms: D000235:Adenolymphoma / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D016131:Lymphocyte Subsets; D016246:Lymphocytes, Tumor-Infiltrating; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000473:pathology*; D012044:Regression Analysis